... on the Provision of Public Goods, IV', Journal of Public Economics, 15: 295±310 Mitchell, R C., and Carson, R T (1989), Using Surveys to Value Public Goods: The Contingent Valuation Method, Resources ... S Brookshire, and W D Schulze (eds.), Valuing Environmental Goods, Rowman and Allanheld, Totowa, NJ ÐÐ Heberlein, T A., and Kealy, M J (1983), `Hypothetical Bias in Contingent Valuation: Results ... Economics and Philosophy, 1: 189±211 Clarke, E H (1971), `Multipart Pricing of Public Goods' , Public Choice, 11: 19±33 Collard, D (1978), Altruism and Economy, Martin Robertson, Oxford Douglas, M., and...